(a) Field of the Invention
The present invention relates to a multi-source shadowless operating lamp, and particularly to a multi-source shadowless operating lamp which has dissipation substrates, a plurality of LED (Light Emitting Diode) sets being mounted on the dissipation substrates and having different angles for respectively corresponding to a fixed light field, and a link element automatically adjusting the angles for varying height of light, thereby overlapping a light field and preventing against dust.
(b) Description of the Prior Art
Optical light apparatus applied on medical operation is generally shadowless and is distinguished from ordinary illuminative devices. A conventional shadowless operating lamp has a central base on a center thereof, and forms a fixed light field below the central base. A plurality of illumination bodies are symmetrically around the central base. The illumination bodies are pivoted to the central base for adjusting angles with respect to light sources. Each illumination body has a cover for pivoting to the central base, and a plurality of mounting bases in the cover for retaining to a dissipation plate. The mounting bases receive a plurality of light emission diodes (LEDs). A spotlight lens controls the LEDs to adjust light focus spot, focusing light of the LEDs on a common focus spot, and adjust the illumination bodies to focus on a common target field. Thus, a light field of a Gaussian distribution is formed on the target field.
The conventional shadowless operating lamp has deficiencies in structure as follows:    1. Surgeons need to adjust light field of the illumination bodies to discern operating positions. In general, the covers of the illumination bodies are pushed to rotate the illumination bodies relative to the central base. Due to the pivoting connection between the covers and the central base, when the angles therebetween are changed, dust may remain on joints between the covers and the central base, which can not comply with dustless standard in surgical room and increase cost of sanitary and maintenance.    2. The LEDs are mounted on the mounting bases and fixed on the dissipation plates. The generated heat of the LEDs tends to damage ambience thereof. In addition, heat of the LEDs is indirectly conducted to the dissipation plate through the mounting bases, influencing dissipation effect and shortening lifespan of the LEDs.    3. Positions of the LEDs are different, so an extra spotlight lens is required to adjust the LEDs of the illumination body on a common focus spot. This is inconvenient and increases expense of the extra spotlight lens.